Smalling Kelly L, Aelion C Marjorie
Department of Environmental Health Sciences, Room 311, University of South Carolina, 800 Sumter Street, Columbia, SC 29208, USA.
Chemosphere. 2006 Jan;62(2):188-96. doi: 10.1016/j.chemosphere.2005.05.042. Epub 2005 Aug 25.
The degradation and distribution potential of atrazine, a persistent triazine herbicide, into three chemical fractions were measured in coastal aquatic sediments in the laboratory over time. Sediments with varying organic carbon contents were extracted with an organic solvent followed by an alkali hydrolysis reaction, and atrazine, deethylatrazine (DEA) and deisopropylatrazine (DIA) were quantified in the aqueous, solvent, and basic fractions using gas chromatography-mass spectrometry. The total amount of atrazine and its metabolites recovered after 95 days varied by site and ranged from 5% to 30% in which 95% was atrazine found primarily in the solvent fraction. Sediment organic carbon was positively correlated with the distribution of atrazine into the basic fraction and the decline in the total amount recovered. No DIA was detected in laboratory spiked sediments and transformation to DEA was limited in all sediments and made up less than 1% of the mass balance. The production and persistence of DEA were inversely correlated to organic carbon; sediments with less carbon and limited binding sites had increased formation and persistence of DEA. A secondary metabolite, methylated atrazine (M-ATR) not previously documented to be derived from atrazine, was chemically produced, detected in all sediments and time points, and concentrations were an order of magnitude higher than DEA. Based on results from spiked estuarine sediments, atrazine and M-ATR may have the potential to persist in the environment while DEA and DIA may not be an ecological threat due to their limited formation.
在实验室中，随着时间的推移，对一种持久性三嗪类除草剂阿特拉津在沿海水生沉积物中降解为三种化学组分的情况及其分布潜力进行了测定。用有机溶剂萃取不同有机碳含量的沉积物，随后进行碱水解反应，使用气相色谱 - 质谱法对水相、溶剂相和碱性相中阿特拉津、去乙基阿特拉津（DEA）和去异丙基阿特拉津（DIA）进行定量。95天后回收的阿特拉津及其代谢物总量因地点而异，范围在5%至30%之间，其中95%为阿特拉津，主要存在于溶剂相中。沉积物有机碳与阿特拉津在碱性相中的分布以及回收总量的下降呈正相关。在实验室加标沉积物中未检测到DIA，且在所有沉积物中向DEA的转化都很有限，占质量平衡的比例不到1%。DEA的产生和持久性与有机碳呈负相关；碳含量较低且结合位点有限的沉积物中DEA的形成和持久性增加。一种先前未被记录为由阿特拉津衍生而来的次生代谢物——甲基化阿特拉津（M - ATR）被化学合成，在所有沉积物和时间点均被检测到，其浓度比DEA高一个数量级。基于加标河口沉积物的结果，阿特拉津和M - ATR可能在环境中具有持久性，而DEA和DIA由于其形成有限可能不会构成生态威胁。
